Edouard’s good fortune was running into opponents who made a series of miscalculations, and he had the skill to take advantage of those errors.

The tournament started well for Edouard, who was seeded third in a field that included almost 40 grandmasters. He won three of his first four games and drew the other. His first piece of good fortune came in Round 5, when he faced Abhijeet Gupta of India, the No. 12 seed, who had White.

Gupta was enterprising in the opening and managed to break apart the pawns guarding Edouard’s king. After 26 moves, the players reached the position in the left diagram.

A round later, against Vladimir Akopian of Armenia, the No. 2 seed, Edouard made an error of his own at Move 25 and lost a key central pawn. But he got lucky again. Akopian soon made a mistake that evened the chances. The game stretched for 74 moves, with Akopian adding to his mistakes and finally losing.

After a draw in Round 7 and a convincing win in Round 8, Edouard faced Anton Korobov of Ukraine, the top seed, in the final round. Edouard soon found himself in trouble, again.

In the diagram on the right, Korobov, who was White, could simply have played 30 Qd3 to seize a significant edge in the endgame after 30 ... cd3 31 Ree7 Bf6 32 Red7 Rd7 33 Rd7.

Instead, the game went 30 Rae7 Rf3 31 gf3 Qf3. At that point, Korobov should have played 32 Rd2 to keep an advantage. But Edouard’s lucky streak continued when Korobov made a fatal mistake with 32 Qe4.

He resigned after 32 ... Rg5 because the only way to avoid checkmate would have been to give up his queen by 33 Qg4.

A version of this article appears in print on April 20, 2014, on Page A17 of the New York edition with the headline: Making the Most of Opponents’ Mistakes. Order Reprints|Today's Paper|Subscribe